Transforming bulk Si into the nanometer scale results in efficient room temperature emission of visible light. One extensively studied variant of nano-scaled Si is porous Si (p-Si). Porous features are normally created in bulk Si through some type of electrochemical etching technique. Quantum confinement effects and surface effects control the electronic and optical properties of this material. p-Si is an interesting material for both the viewpoints of fundamental physics and device applications. Although much is known about this material, the exact origin of light emission is still a topic of debate in the literature.